1. Field of the Invention
The subject invention generally pertains to electronic power conversion circuits, and more specifically to high frequency, switched mode power electronic converter circuits.
2. Description of Related Art
Power conversion circuits, in general, create either a pulsed current wave form or a continuous triangular wave form at the terminals of the circuit. To provide an electromagnetically compatible interface, filters are often provided at the terminals. The size and cost of the filters depends on the frequency content and magnitude of the AC ripple components of the terminal currents. A terminal with a pulsed current wave form almost always requires a filter. A triangular terminal current wave form may require a filter although one smaller than would be required by a pulsating current. In addition to the terminal filtering schemes there are ripple current steering schemes that add windings to the chokes and transformers and capacitors to provide a preferred path for AC currents away from the terminals. There are some circuits with enhanced electromagnetic compatibility (EMC) that have been known for some time, but to date there has been no revelation of universally applicable defined methods that describe how to synthesize EMC enhanced circuits from equivalent circuits with no EMC enhancements.
One example of an EMC enhanced circuit is the Cuk converter, illustrated in FIG. 2. The Cuk converter has the same input-to-output transfer function as the non-isolated flyback converter, illustrated in FIG. 1. No universally applicable synthesis method has been described that allows a designer to transform the flyback converter into the Cuk converter. The Cuk converter also provides improved AC performance by comparison to the flyback converter. The description of universally applicable synthesis methods that enable a designer to transform known circuits into circuits with EMC and AC performance enhancements is the subject matter of this invention.
One object of the subject invention is to provide a simple universally applicable synthesis method that can convert any three terminal network with one terminal current non-pulsating into an equivalent three terminal network with all terminal currents non-pulsating.
Another object of the subject invention is to provide a simple universally applicable synthesis method that can convert three terminal networks with an inductor winding in series with one terminal into equivalent three terminal networks with ripple current cancellation at all terminals.
Another object of the subject invention is to provide a simple universally applicable synthesis method that can convert a magnetically coupled two terminal network containing at least one switch and one coupled winding into an equivalent network in which the common mode currents into or out of the subject coupled winding is significantly reduced or eliminated.
Another object of the subject invention is to provide a simple universally applicable synthesis method that can convert a magnetically coupled two terminal network containing at least one switch and one coupled winding into an equivalent network in which the common mode currents into or out of the subject coupled winding is significantly reduced or eliminated and the terminal ripple currents are canceled.
Another object of the subject invention is to provide a simple universally applicable synthesis method that can convert a full bridge circuit with pulsating terminal currents into an equivalent full bridge circuit with non-pulsating terminal currents with terminal ripple current cancellation.
Another object of the subject invention is to provide a simple universally applicable synthesis method that can convert a half bridge circuit with pulsating terminal currents into an equivalent half bridge circuit with non-pulsating terminal currents with terminal ripple current cancellation.
Another object of the subject invention is to provide a simple universally applicable synthesis method that can convert a stacked full bridge circuit with pulsating terminal currents into an equivalent stacked full bridge circuit with non-pulsating terminal currents.
Another object of the subject invention is to provide a simple universally applicable synthesis method that can convert a stacked full bridge circuit with pulsating terminal currents into an equivalent stacked full bridge circuit with non-pulsating terminal currents with terminal ripple current cancellation.
Another object of the subject invention is to provide simple universally applicable synthesis methods that can improve the AC performance characteristics of the circuits to which the synthesis methods are applied.